1. Technical Field
The present invention relates to a coloring composition, a coloring radiation-sensitive composition, a production method of a polymer, a pattern forming method, a color filter and a production method thereof, and a solid-state imaging device.
2. Background Art
As production methods of color filters used in liquid crystal displays or solid-state imaging devices, a dyeing method, a printing method, an electrodeposition method, and a pigment dispersion method are known.
Of these, the pigment dispersion method is a method in which a color filter is produced by photolithography using a coloring radiation-sensitive composition in which a pigment is dispersed in various radiation-sensitive compositions, and has an advantage of being stable to light, heat or the like since pigments are used. Positional accuracy is also high since patterning is carried out by photolithography, therefore, the method is widely used as a suitable method in producing color filters for large-screen and high-definition color display.
However, in recent years, high definition has become more required in color filters for solid-state imaging devices, and there have been problems with conventional pigment dispersion methods such that resolution is not improved and color irregularity occurs due to coarse particles of the pigments. Therefore, conventional pigment methods are not suitable for applications in which color filters having fine patterns such as a solid-state imaging device are required.
In order to solve such problems, the use of dyes has been proposed, however, radiation-sensitive compositions containing dyes have new problems (see, for example, Patent Document 1). That is, (1) Common dyes have low solubility in either an aqueous alkali solution or an organic solution, therefore, it is difficult to obtain a liquid radiation-sensitive composition of a target spectrum. (2) Dyes are often shown to interact with other components in a radiation-sensitive composition, therefore, it is difficult to adjust solubility (developability) of the cured area and non-cured area. (3) When a molar extinction coefficient (ε) of a dye is low, a large amount of dye needs to be added, resulting in problems such as lowering a curing property of the composition, heat resistance after curing, developability of a non-cured area or the like since the amount of other components such as a polymerizable compound, a binder, or a photopolymerization initiator in the radiation-sensitive composition has to be reduced. (4) Dyes are generally inferior in light resistance and heat resistance compared to pigments.
For this reason, several technologies have been proposed to improve stability of the dye by making the dye a dye polymer by polymerizing the dye with a monomer component having a dye skeleton. By polymerizing the dyes, stability is improved and reduction in color irregularity becomes possible compared to the case using pigments, however, regarding developability when this coloring composition is applied to a radiation-sensitive composition, there is still room for further improvement.
Meanwhile, a method has been proposed in which an alkali soluble binder having an acidic group and of which a glass transition temperature is 100° C. to 350° C. is used and also, the content of an unreacted monomer included in the binder is less than or equal to 3 mass % in order to improve developability and reduce the residues (For example, see JP2004-286810A).